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IceCube: Status and IceCube: Status and ResultsResults IntroductionIntroduction Detector Description and StatusDetector Description and Status Physics with IceCube, Some Recent Physics with IceCube, Some Recent
ResultsResults ConclusionsConclusions AcknowledgementAcknowledgement
Ali R. Fazely, Southern Universityfor the IceCube Collaboration
icecube.wisc.eduMiami Conference, 12/14-19/2010
Latest News!Latest News!Completion of the IceCube Completion of the IceCube
DetectorDetector
The IceCube Detector will be fully The IceCube Detector will be fully installed by Sunday 12/19/2010 installed by Sunday 12/19/2010 and the press release from NSF and the press release from NSF will follow on Monday.will follow on Monday.
Miami Conference, 12/14-19/2010
What is IceCube?What is IceCube?
A gigaton neutrino detector funded A gigaton neutrino detector funded through the National Science through the National Science Foundation and EU funding agenciesFoundation and EU funding agencies
We are in our 7We are in our 7thth project year and will project year and will complete construction in 2011complete construction in 2011
We are building the largest Neutrino We are building the largest Neutrino Telescope at the geographic South PoleTelescope at the geographic South Pole
The project is on schedule and it has The project is on schedule and it has just begun to produce exciting physics.just begun to produce exciting physics.
http://icecube.wisc.edu/http://icecube.wisc.edu/
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44
IceCube IceCube CollaborationCollaboration
Bartol Research Inst, Univ of Delaware, USAPennsylvania State University, USAUniversity of Wisconsin-Madison, USAUniversity of Wisconsin-River Falls, USALBNL, Berkeley, USAUC Berkeley, USAUC Irvine, USA
Univ. of Alabama, USAClark-Atlanta University, USAUniv. of Maryland, USAUniversity of Kansas, USASouthern Univ. and A&M College,
Baton Rouge, LA, USAUniversity of Alaska, Anchorage, USAGeorgia Tech, USAOhio State, USA
Université Libre de Bruxelles, BelgiumVrije Universiteit Brussel, BelgiumUniversité de Mons-Hainaut, BelgiumUniversiteit Gent, BelgiumUniversität Mainz, GermanyDESY Zeuthen, GermanyUniversität Wuppertal, GermanyUniversität Dortmund, Germany
Humboldt Universität, GermanyMPI, Heidelberg, GermanyRuhr-Universität, Bochum, GermanyBonn Universität, GermanyRWTH Aachen, GermanyUppsala Universitet, SwedenStockholm Universitet, SwedenKalmar Universitet, SwedenUniversity of Oxford, UKEPFL, Lausanne, Switzerland
Chiba University, Japan
University of Canterbury, Christchurch, New Zealand
36 collaborating institutions
University ofWest Indies
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University of Alberta -Edmonton, Alberta Canada
55
Cosmic Rays: A century old Cosmic Rays: A century old puzzlepuzzle
Victor HessNobel Prize1936
Balloon flights1911-1913
•Power law over many decades
•Origin UncertainCosmic ray spectrumCosmic ray spectrum
Extra Galactic?
Galactic?
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South Pole with IceCubeSouth Pole with IceCube
South Pole
runway
Amundsen-Scott South Pole Station
IceCube
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77
AMANDA
19 Strings
677 Modules
first data 2005upgoing muon 18. July 2005
IceTop
InIce
Air shower detector
threshold ~ 300 TeV
80-86
Strings,
60 Optical
Modules per
String
Completion:January 2011
2008: 40 Strings (This Analysis)
2009: 59 Strings
2010: 79 Strings
Deep Core
The IceCube Detector
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Observing the Universe
Nuclei are easy to detectwith balloon and satellites.Lack directional information and limited to sub-PeV energies.
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http://mwmw.gsfc.nasa.gov/mmw_allsky.html
Observing the Universe
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1010
Neutrinos as Cosmic Neutrinos as Cosmic MessengersMessengers
Protons: deflected by magnetic fields.
p
Photons: easily absorbed by CMB backgrounds.
γ
Neutrinos: not deflected by magnetic fields. Low interaction cross-section.
ν
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Neutrino interactionsNeutrino interactions
35
μ
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(NC) X )τν(τν O16)τν(τν
(NC) X)μν(μν O16)μν(μν
(NC) X )eν(eν O16 )eν(eν
(CC) X)(τ τ O16)τν(τν
(CC) X)μ(μ O16)μν(μν
(CC) X )(e e O16 )eν(eν
DDigitaligital OOpticalptical MModuleodule
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1414
Sensing Neutrino LightSensing Neutrino Light
Measure arrival time of every Measure arrival time of every photonphoton
2x 300MHz waveform digitizers2x 300MHz waveform digitizers1x 40 MHz FADC digitizer1x 40 MHz FADC digitizerCan trigger in coincidence w/ Can trigger in coincidence w/
neighbor DOMneighbor DOMTransmits data to surface on Transmits data to surface on
requestrequestData sent over 3.3 km twisted Data sent over 3.3 km twisted
pair copper cablepair copper cableKnows the time to within 3 Knows the time to within 3
nanoseconds to all other DOMs nanoseconds to all other DOMs in the icein the ice
Clock stability: 10-10 ≈ 0.1 nsec / secSynchronized periodically to precision of O(2 nsec)
IceCube “Digital Optical Module” (DOM)
Power consumption: 3W
Hamamatsu R7081, 10 inch PMT
33 cm Benthosphere
PMT base
Main board
Flasher Board
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IceCube IceCube ConstructionConstruction
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1616
Event Event TopologiesTopologies ννμμ produce μ tracks produce μ tracks
– Angular Res ~ 0.7Angular Res ~ 0.70 0
– Eres log(E) ~ 0.3Eres log(E) ~ 0.3 ννe e CC, νCC, νx x NC create showers NC create showers
– ~ point sources, ’cascades’ ~ point sources, ’cascades’ – Eres log(E)=0.1-0.2Eres log(E)=0.1-0.2
ννττ double bang events, others double bang events, others
Muon – IC 40 data
16 PeV ντ simulation350 TeV νe simulationMiami Conference, 12/14-19/2010
Real and Possible ET Neutrino Real and Possible ET Neutrino SourcesSources
The The sunsun
Supernova 1987ASupernova 1987A
Gamma Ray Gamma Ray BurstsBursts
Active Galactic Active Galactic NucleiNuclei
Dark Matter?Dark Matter?
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Plethora of PhysicsPlethora of Physics Neutrinos from the sun and SN1987A have Neutrinos from the sun and SN1987A have
been observedbeen observed IceCube can search for SN event with high IceCube can search for SN event with high
sensitivity.sensitivity. We want to search for higher energy We want to search for higher energy
neutrinos and open up a new window to neutrinos and open up a new window to the universe. the universe.
Searches also can be done for neutrino Searches also can be done for neutrino oscillations, wimps, magnetic oscillations, wimps, magnetic monopoles…. monopoles….
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The majority of triggers in IceCube are from amospheric muons
We record over 6 x109 muons and 74,000 atmospheric muon neutrinos.
Backgrounds
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2020
•Main Background to Astrophysical Search
•Created by high energy cosmic rays
colliding with O and N in the Earth’s
atmosphere
•Conventional (Pions & Kaons) vs. Prompt
(Charmed Mesons)
•Conventional ~ E-3.7 Spectrum
•Prompt ~ E-2.7 Spectrum
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Sean Grullon, Ph.D. thesis, UW-Madison, Fall 2010
O
2121
Flux Models and LimitsFlux Models and Limits
Upper Limit on Astrophysical E-2 νμ
E2 < 8.9 x 10-9 GeV cm-2 s-1 sr-1
4.54 < log10(E /GeV) < 6.84
Upper Limit on Astrophysical E-2 νμ
E2 < 8.9 x 10-9 GeV cm-2 s-1 sr-1
4.54 < log10(E /GeV) < 6.84
This Result
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Sean Grullon, Ph.D. thesis, UW-Madison, Fall 2010
Astrophysical Model TestsAstrophysical Model Tests
5σ
5σ
5σ
3σ
This Result
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Sean Grullon, Ph.D. thesis, UW-Madison, Fall 2010
Atmospheric Neutrino Atmospheric Neutrino SpectrumSpectrum
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Sean Grullon, Ph.D. thesis, UW-Madison, Fall 2010
2424
What a Discovery Would Look What a Discovery Would Look Like?Like?
Astrophysical Evidence
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Sean Grullon, Ph.D. thesis, UW-Madison, Fall 2010
Results Results • Diffuse Astrophysical Muon Neutrino Diffuse Astrophysical Muon Neutrino
Upper Limit is Upper Limit is EE22 < 8.9 x 10 < 8.9 x 10-9-9 GeV cm GeV cm-2 -2 ss-1 -1 srsr-1-1
Optimistic Astrophysical models ruled Optimistic Astrophysical models ruled out: No surprises and IceCube is in it for out: No surprises and IceCube is in it for the long haulthe long haul
Atmospheric neutrino spectrum Atmospheric neutrino spectrum measured at high energies from 332.4 measured at high energies from 332.4 GeV to 83.7 TeVGeV to 83.7 TeV
No Evidence for Prompt Atmospheric FluxNo Evidence for Prompt Atmospheric Flux Prompt Atmospheric Models constrained Prompt Atmospheric Models constrained
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Sean Grullon, Ph.D. thesis, UW-Madison, Fall 2010
Point Source Search (IC40)Point Source Search (IC40)
40-string (6 months) All sky search 40-string (6 months) All sky search Livetime: 175.5 days Livetime: 175.5 days 17777 events (6796 up, 10981 down)17777 events (6796 up, 10981 down) Hot spot at Hot spot at α α = 7h 40m= 7h 40m, , δ δ = 15.4°= 15.4° Pre-trial significance of 10Pre-trial significance of 10-4.4-4.4
Post-trials p-value after R.A. scrambling = 61% (all sky) Post-trials p-value after R.A. scrambling = 61% (all sky) Improved signal efficiency, acceptance and background rejection. Improved signal efficiency, acceptance and background rejection.
Northern Sky:ν Background
Southern Sky:μ Background
J. Dumm et al., ICRC 2009 (Lodz)
Preliminary
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Gamma Ray Bursts (22 strings)Gamma Ray Bursts (22 strings)
Source stacking: 41 GRBs observed by SWIFT, etc., Source stacking: 41 GRBs observed by SWIFT, etc., summed to estimate a total neutrino fluxsummed to estimate a total neutrino flux
Upper limits set for precursor, prompt neutrino fluxUpper limits set for precursor, prompt neutrino flux Full detector: Full detector: 55σσ GRB neutrino observation GRB neutrino observation within within
2 years (assuming Waxman-Bahcall flux)2 years (assuming Waxman-Bahcall flux)
A. Kappes et al., ICRC 2009 (Lodz)
predicted
90% C.L.
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Gamma Ray Bursts, IC-40 and IC-Gamma Ray Bursts, IC-40 and IC-5959(Preliminary)(Preliminary)
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• Relative intensity of the cosmic ray event rate: for each declination belt of width 3°, the plot shows the number of events relative to the average number of events in the belt. •First Observation of the Anisotropy for the southern sky.•Abbasi et al., ApJ, 718, L194, 2010
Cosmic ray anisotropy measurement
0o 360o
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RelativeRelative Intensity of Cosmic Rays (IC22, Intensity of Cosmic Rays (IC22, IC40IC40 & & IC59IC59) )
Year Rate (Hz) LiveTime(Days) CR Median Energy (TeV)
Median Angular Resolution (degrees)
Number of Events(billion)
2007-IC22 240 ~226 ~19 3 ~4
2008-IC40 780 ~324 ~19 3 ~15
2009-IC59 1300 ~324 ~19 3 ~35
IC40
IC22
0o 360o
IC59
Rela
tive In
tensi
ty
Right AscensionAbbasi et al., ApJ, 718, L194, 2010
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IC40 & IC59 results are preliminary
Solar time
Sidereal Time
0o
360o
Observation of the solar dipole effect and the absence of the anti-siderealSignal insures the reliability of the observation.
Anti-sidereal time
Systematic checks (IC59):1-d projection
A1 (10-4) (sidereal)
Φ1(deg) (sidereal)
A1 (10-4)(solar)
Φ1(deg)(solar)
A1(10-4)(anti-sidereal)
Φ1(deg)(anti-sidereal)
7.2±0.1 55.1±0.89 1.7±0.1 90.9±3.6 0.45±0.11 36.7±14.1
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Sidereal anisotropy by Tibet Array and Sidereal anisotropy by Tibet Array and IceCubeIceCube
IceCube-5920 TeV
Tibet Array5 TeV
• Data from May 2009-2010• Median angular resolution 3o
• Median Energy resolution 20 TeV• Anisotropy is a continuation of previously
measured large scale anisotropy observed in northern locations.
Relative Intensity
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Results SummaryResults Summary First skymap reporting a significant large scale anisotropy in First skymap reporting a significant large scale anisotropy in
the southern hemisphere sky. the southern hemisphere sky. At 20 TeV the anisotropy is in remarkable agreement with At 20 TeV the anisotropy is in remarkable agreement with
previous northren sky measurements.previous northren sky measurements. The result is supported by the observation of solar dipole The result is supported by the observation of solar dipole
effect together with the absence of the anti-sidereal signal. effect together with the absence of the anti-sidereal signal. At higher energies around (400 TeV) the anisotropy At higher energies around (400 TeV) the anisotropy
disappears.disappears. Source for large scale anisotropy is unknown Source for large scale anisotropy is unknown Galactic Environment?Galactic Environment? SNR inducing a large scale anisotropy?SNR inducing a large scale anisotropy?
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Supernova Detection with Supernova Detection with IceCubeIceCube
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Supernova 1987ASupernova 1987A
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Type II SupernovaType II SupernovaOn average, every 30 years or so in our galaxy a massive star with M > 8M explodes
Gravitational instability due to C, O, and Si fusion into a Fe – Ni core
Gravity overcomes the electron pressure and collapsebegins; nuclear densities are reached with a core radius of R ~ 10 km, with E = GM~ 10 km, with E = GM22/R ~/R ~ 10105959 MeV MeV
Neutrinos are trapped in the neutrinosphere and materials bounce, cooling of the neutron star by neutrino emission, shock wave and explosion Ekin ~ 0.01 E.~ 0.01 E.
99% of the energy is carried off by neutrinos!99% of the energy is carried off by neutrinos!Miami Conference, 12/14-19/2010
Totani et al., (1998)Totani et al., (1998)
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Neutrino Spectra from SN
SN87A EventsSN87A EventsIMB & KamiokaIMB & Kamioka
IMBI
KAMI
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Electron anti-neutrino Electron anti-neutrino spectrumspectrum
Takahashi and Sato, hep-ph/0905070v3, Prog.Theor. Phys. 109 (2003) 919-931
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XY Hit distribution for SN positrons, i3geant , XY Hit distribution for SN positrons, i3geant , average DOM QE, 27% higher for DeepCore average DOM QE, 27% higher for DeepCore
(AHA Ice Model)(AHA Ice Model)
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ZX Hit distribution for SN positrons, ZX Hit distribution for SN positrons, i3geant , average DOM QE, 27% higher for i3geant , average DOM QE, 27% higher for
DeepCore (AHA Ice Model)DeepCore (AHA Ice Model)
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IceCube SN Sensitivity IceCube SN Sensitivity For a SN with 10 M at a distance of 10 kpc, the For a SN with 10 M at a distance of 10 kpc, the
dominant neutrino reaction isdominant neutrino reaction is ννeep p ne ne+ + with a flux-integrated CC cross with a flux-integrated CC cross section of:section of:
σσ = = 0.24 x 10 0.24 x 10-40-40 cm cm2 2 (Vogel and Beacom, Struma and (Vogel and Beacom, Struma and Vissani, Llewellyn and Smith) at T = 5 MeVVissani, Llewellyn and Smith) at T = 5 MeV
The SN detection method in IceCube is based on an The SN detection method in IceCube is based on an overall count-rate increase in the DOM’s. overall count-rate increase in the DOM’s.
We expect a sensitive range of ~ 60 kpc (LMC)We expect a sensitive range of ~ 60 kpc (LMC)
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IceCube SN Sensitivity IceCube SN Sensitivity
Recently, our Geant MC indicates that a Recently, our Geant MC indicates that a trigger based on two-DOM coincidence trigger based on two-DOM coincidence may be possible.may be possible.
This method will substantially reduce the This method will substantially reduce the background and will dramatically background and will dramatically increase the sensitivity of the IceCube increase the sensitivity of the IceCube detector to well beyond the LMC.detector to well beyond the LMC.
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ConclusionsConclusions IceCube is almost complete and will be fully IceCube is almost complete and will be fully
operational soon (78 + 8 DeepCore). operational soon (78 + 8 DeepCore). Data has been analyzed for diffuse neutrinos, Data has been analyzed for diffuse neutrinos,
anisotropy, GRB’s, point sources …anisotropy, GRB’s, point sources … No surprises yet, but with the full detector No surprises yet, but with the full detector
operating, we are eager to analyze future data operating, we are eager to analyze future data and ever hopeful!and ever hopeful!
SN detection capability of IceCube looks ever SN detection capability of IceCube looks ever more promising. more promising.
Stay tuned!Stay tuned!
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AcknowledgementAcknowledgement
We gratefully We gratefully acknowledge the acknowledge the funding of our project at Southern from funding of our project at Southern from a National Science Foundation, Major a National Science Foundation, Major Research Equipment grant through the Research Equipment grant through the University of Wisconsin Board of University of Wisconsin Board of Regents. Regents.
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